Method and system for producing ammonium nitrate and method for retrofitting a system for producing ammonium nitrate

Abstract

The present invention relates to a method for producing ammonium nitrate in a neutralisation reaction of ammonia and nitric acid, wherein a reaction stream containing ammonium nitrate and water is obtained. For the purpose of concentration, water is separated from the reaction stream and a concentrate stream is obtained. For the purpose of further concentration, additional water is separated from the concentrate stream and a final concentrate stream is obtained. The reaction heat of an additional neutralisation reaction of ammonia and nitric acid is used for heating during further concentration. The invention also relates to a corresponding system for producing ammonium nitrate, in which said method is carried out, and to a method for retrofitting conventional systems for producing ammonium nitrate in order to enable said method to be carried out.

Description

[0001] Process and plant for the production of ammonium nitrate as well as process for

[0002] Conversion of a plant for the production of ammonium nitrate

[0003] The invention lies in the field of chemical process engineering and chemical plant construction and relates to a process for the production of ammonium nitrate, comprising the steps a) combining ammonia and nitric acid, whereby a reaction stream containing ammonium nitrate and water is obtained, b) separating water from the reaction stream, whereby a concentrate stream and a water stream are obtained, and c) heating the concentrate stream and separating water from the concentrate stream, whereby a final concentrate stream is obtained, with the features of claim 1.

[0004] The invention further relates to a plant for the production of ammonium nitrate, the plant comprising a process neutralizer, a primary concentrator and a product concentrator, wherein the primary concentrator is arranged downstream of the process neutralizer and the product concentrator is arranged downstream of the primary concentrator, wherein the process neutralizer is configured and adapted to generate a reaction stream containing ammonium nitrate and water from supplied ammonia and supplied nitric acid, wherein the primary concentrator is configured and adapted to separate water from the reaction stream and obtain a concentrate stream, wherein the product concentrator has a heat exchanger and is configured and adapted to heat the concentrate stream in the product concentrator, wherein the heat exchanger of the product concentrator has a first side and a second side which are in thermal contact with each other.wherein the first side of the heat exchanger is configured and adapted to pass the concentrate stream through it, and the second side of the heat exchanger is adapted to pass a heat medium stream through it, in order to heat the concentrate stream as it passes through the first side of the heat exchanger in thermal contact with the heat medium stream and to evaporate water from the concentrate stream and separate it from the concentrate stream, with the features of claim 11. Finally, the invention relates to methods for converting a plant for the production of ammonium nitrate, the plant comprising a process neutralizer, a primary concentrator and a product concentrator, wherein the primary concentrator is arranged downstream of the process neutralizer and the product concentrator is arranged downstream of the primary concentrator, wherein the process neutralizer is configured and adapted,to generate a reaction stream containing ammonium nitrate and water from supplied ammonia and supplied nitric acid, wherein the primary concentrator is configured and adapted to separate water from the reaction stream and obtain a concentrate stream, wherein the product concentrator has a heat exchanger and is configured and adapted to heat the concentrate stream through the heat exchanger, thereby evaporating and separating water from the concentrate stream to obtain a final concentrate stream, wherein the heat exchanger of the product concentrator has a first side and a second side which are in thermal contact with each other, wherein the first side of the heat exchanger is configured and adapted to pass the concentrate stream through it, and the second side of the heat exchanger is adapted to pass a heat medium stream through it.to heat the concentrate stream as it passes through the first side of the heat exchanger in thermal contact with the heat medium stream and to evaporate water from the concentrate stream and separate it from the concentrate stream, with the features of claim 19, and a method for converting a plant for the production of ammonium nitrate, the plant comprising a process neutralizer, a primary concentrator and a product waste concentrator, wherein the primary concentrator is arranged downstream of the process neutralizer and the product waste concentrator is arranged downstream of the primary concentrator, wherein the process neutralizer is configured and adapted to generate a reaction stream containing ammonium nitrate and water from supplied ammonia and supplied nitric acid, wherein the primary concentrator is configured and adapted to separate water from the reaction stream and obtain a concentrate stream.wherein the product concentrator is set up and adapted to heat the concentrate stream and thereby evaporate and separate water from the concentrate stream to obtain a final concentrate stream, having the features of claim 20.

[0005] Ammonium nitrate (NH4NO3) is a major component of many fertilizers and is also used as a propellant and explosive. Since the development of the Haber-Bosch process for the production of ammonia (NH3) and the Ostwald process for the production of nitric acid (HNO3), ammonium nitrate has been produced on an industrial and laboratory scale from these two reactants in a highly exothermic reaction.

[0006] Neutralization reaction NH3 NH4NO3 is obtained, whose molar reaction enthalpy is -146 kJ / mol. For this, the two reactant streams are fed into a neutralizer (neutralization reactor), in which the neutralization reaction takes place. During the neutralization reaction, ammonium nitrate is produced from the two reactants, which under standard conditions are normally in liquid form (nitric acid) or gaseous form (ammonia). Ammonium nitrate is normally in solid form under standard conditions. Since ammonium nitrate is explosive, decomposition can occur at excessively high temperatures and / or with certain impurities or additives, which must be avoided for reasons of safety, economy, and ecology.Therefore, a continuous process is generally chosen, yielding ammonium nitrate in solution as the product stream. This solution may contain residual amounts of reactants (ammonia and nitric acid) in dissolved form, in addition to the solvent (usually water) and ammonium nitrate. A portion of the product stream is diverted and processed for further use, while the remainder is recirculated back into the neutralizer, where it serves as a solvent for the reactants and the product. This recirculation provides a sufficiently large heat storage capacity to absorb the heat energy generated during neutralization and prevent overheating. The diverted portion of the product stream is concentrated, with some of the solvent being removed, resulting in a concentrated stream containing a high concentration of ammonium nitrate.

[0007] For energy-optimized reaction control in the production of ammonium nitrate, it is necessary, due to the strongly exothermic nature of the neutralization reaction, to utilize the resulting heat of reaction (heat of reaction) highly efficiently by using it as waste heat as completely as possible to heat different process streams.

[0008] One process approach involves performing concentration via pressure reduction after the neutralization reaction. In this approach, some of the waste heat generated during the neutralization reaction is used to evaporate and remove solvents in the diverted product stream. At least some of the solvent vapor (usually water vapor) produced during the concentration of the product stream in the first pressure reduction stage is either under low pressure (even though the actual neutralization reaction takes place under pressure, in this case the neutralization is referred to as "vacuum neutralization" because the vapors are generated at low pressure) or under high pressure (in this case the neutralization is referred to as "pressure neutralization" because the vapors are generated at high pressure).The solvent vapor generated during vacuum neutralization contains only a small amount of usable heat energy, making it economically unusable or at best poorly utilized. Therefore, it is condensed by cooling water without the heat energy being recovered. The (heat) energy required for evaporation is provided by injecting live steam, the external generation of which involves additional energy consumption and emissions, and is thus considered disadvantageous. Concentrating the product stream during processing can be achieved, for example, in a product concentrator with a...

[0009] Tube bundle heat exchangers are used, to which steam is supplied as a heating medium, typically generated with fossil fuels, and which is passed through the tube bundle heat exchanger with the product stream to be concentrated, whereby the steam condenses into steam condensate and at the same time water from the product stream evaporates.

[0010] Another process approach involves obtaining high-pressure steam after the neutralization reaction in a first pressure reduction stage. Such a process enables the production of ammonium nitrate concentrate without the use of additional live steam. For example, a process is known from DE 1179543 ​​in which the heat of reaction is used to concentrate the final product and to preheat the reactant streams. In this process, aqueous nitric acid and ammonia (gaseous) react with each other in a neutralizer at approximately 170 °C and an absolute pressure of approximately 4 bara. In the upper part of the neutralizer, the product stream flows around the tubes of a shell-and-tube heat exchanger, through which it is cooled to a temperature of approximately 135 °C.The cooled product stream is depressurized to an absolute pressure of approximately 1 bar, during which solvent evaporates as vapors in an evaporator, reducing the product stream temperature by about 10 °C. A portion of the product stream is diverted, while the remainder is recirculated back to the neutralizer. The diverted portion is depressurized to an absolute pressure of approximately 0.16 bar and heated by the vapors generated in the evaporator, causing further solvent evaporation and yielding a concentrated product stream with an ammonium nitrate content of approximately 85% and a temperature of approximately 80 °C. This concentrated product stream is then compressed and fed into the tubes of the neutralizer's shell-and-tube heat exchanger, where it absorbs the heat energy from the reaction within the neutralizer.In this way, the product stream is further evaporated, resulting in an ammonium nitrate content of approximately 98% at an absolute pressure of about 0.27 bara. Obtaining even higher product concentrations is difficult: as the product concentration increases, so does the temperature required to remove more water from the product stream, which would then necessitate exceeding the maximum permissible temperatures to achieve a high product concentration.

[0011] The object of the present invention is to improve existing methods in order to increase the efficiency of waste heat utilization and simultaneously reduce the emission of combustion gases in such systems, which arise when heating process streams. In addition, the invention should also offer the possibility of retrofitting existing systems to increase the efficiency of waste heat utilization and to expand capacity by adding further system components while maintaining safety-relevant aspects, without having to significantly modify and / or decommission the existing system architecture, as this would involve not only a long conversion time but also high investment costs.

[0012] This problem is solved by a process for producing ammonium nitrate with the features specified in claim 1, by a plant for producing ammonium nitrate with the features specified in claim 11, and by a process for converting a plant for producing ammonium nitrate with the features specified in claims 19 or 20. Advantageous embodiments are described in the dependent claims, the following description, and the drawings. In particular, this is a process for producing ammonium nitrate in a neutralization reaction of ammonia and nitric acid, yielding a reaction stream containing ammonium nitrate and water. For concentration, water is removed from the reaction stream to obtain a concentrate stream. For further concentration, additional water is removed from the concentrate stream to obtain a final concentrate stream.For heating during further concentration, the heat of reaction from an additional neutralization reaction of ammonia and nitric acid is used. Furthermore, this involves a suitable plant for the production of ammonium nitrate in which this process is carried out, as well as methods for retrofitting conventional ammonium nitrate production plants to enable this process.

[0013] Such a process for the production of ammonium nitrate therefore comprises the steps a) combining ammonia and nitric acid, yielding a reaction stream containing ammonium nitrate and water, b) separating water from the reaction stream, yielding a concentrate stream and a water stream, and c) heating the concentrate stream and separating water from the concentrate stream, yielding a final concentrate stream and a water stream. Characteristically, the process further comprises the step d) additionally combining further ammonia and further nitric acid, yielding a secondary reaction stream containing ammonium nitrate and water with the release of heat energy.In this process, the heat energy released in step d) during the additional combination of further ammonia and further nitric acid is used to heat the concentrate stream in step c), by the secondary reaction stream transferring heat energy to the concentrate stream and then forming a secondary stream.

[0014] In the first step (step a)), ammonia and nitric acid are combined, resulting in a neutralization reaction (primary neutralization). Ammonia is typically supplied in gaseous form, while nitric acid is typically supplied in liquid form, particularly in concentrated form (i.e., as an aqueous solution of nitric acid with a concentration of at least 50 wt.%, especially at least 55 wt.% or even at least 60 wt.%, preferably at least 65 wt.% or at least 68 wt.%, and in exceptional cases, even higher concentrations). During continuous operation, the reaction stream (first reaction stream, primary reaction stream) is formed, containing primarily ammonium nitrate and water, in addition to small amounts of the two reactants.Furthermore, the reaction stream may contain other components, such as unavoidable impurities, additional solvents, or additives that are advantageous for the reaction process or for the desired final product. In addition to the two reactants, other mass streams can be added to the reaction. For example, the reaction can be carried out in a solvent such as water to facilitate the absorption of heat energy generated during the reaction (thermal conductivity). Such an additional mass stream allows more heat to be removed per unit of time, thus preventing (especially local) overheating of the reaction stream due to the heat of reaction released during the neutralization reaction.In particular, it is also possible to recirculate the reaction stream and return it to the reaction chamber, so that a circulating stream is formed from which only a certain amount is diverted at a time to be used for further processing; the reaction stream can then, in particular, represent the circulating stream from which the undistributed part of the reaction stream is returned to the reaction as a "further mass flow", which can then be used to absorb heat energy.

[0015] Depending on the desired reaction parameters, the reaction can be carried out with an excess of acid (so that stoichiometrically more nitric acid than ammonia is added), with an excess of base (so that stoichiometrically more ammonia than nitric acid is added), or under neutral conditions (so that the stoichiometric amounts of ammonia and nitric acid are equal). A corresponding excess may be used, for example, if it is necessary for process engineering purposes to prevent slippage of the other component. Typically, the reaction is carried out at a pressure of at least 0.1 bara to at most 10 bara (bar(a), bar abs., bar absolute, i.e., at the corresponding absolute pressure). The reaction stream is discharged from the reactor.In the second step (step b)), water is separated from the reaction stream, yielding a concentrated reaction stream (concentrate stream) and a water stream (the "first" water stream from the primary concentration). The concentrate stream therefore contains the (target) product ammonium nitrate at a higher concentration than the reaction stream and has a lower water content.The separation of water typically occurs by changing the pressure (a pressure reduction during pressure relaxation, for example in flash evaporation) and / or by changing the temperature (a temperature increase during heating, for example in thermal evaporation), whereby the water transferred into the gas phase is physically separated as vapor from the remaining liquid phase, for example in a cyclone separator or the like, but other separation methods are also possible in principle, for example those using adsorbents or selective membranes.Generally, water separation occurs after the neutralization reaction and therefore in different parts of the plant (the neutralization reaction takes place in a different part of the plant than the water separation). However, with suitable reaction control, this can also occur in an integrated neutralizer concentrator. The resulting concentrate stream and the resulting water stream are then routed separately. The concentrate stream is subsequently fed into a further treatment process. During separation, the water typically emerges in gaseous form, so the water stream consists predominantly of water vapor. However, it is also possible to condense the water vapor to obtain a liquid water stream. The heat energy released in this process can be used in this or other processes. The water stream can also be treated.For example, the water stream can be treated using mass transfer trays as washing trays (such as bubble-cap trays or Thormann® trays) to purify water produced as steam during gas scrubbing. This is particularly useful for removing (overstoichiometric) residues of acids or bases from the water stream if the neutralization reaction was carried out with an excess of acid or base, as the purified water stream can then be used for further processing or disposal. In the third step (step c)), after separating water from the reaction stream in the second step, the concentrate stream is heated to separate additional water from the concentrate stream as a second water stream (product concentration), thus obtaining a concentrated concentrate stream (final concentrate stream).In this step, the separation of water typically occurs in the manner described in connection with step b), i.e., by changing the temperature. This does not preclude the possibility that, in addition to the temperature increase, the other process conditions may be selected to further promote the separation, for example, by a simultaneous or subsequent pressure reduction. The water stream is typically obtained in gaseous form, i.e., as a steam stream, and can be used separately or disposed of after separation. Product concentration in other devices is preferably possible, for example, in a shell-and-tube heat exchanger used as a falling film evaporator.Prior to this, the gas stream can also be subjected to further processing steps, such as gas scrubbing for purification. Consequently, the further processing or use of the water stream from the secondary concentration typically occurs in the same way as described in step b) in connection with the processing / use of the water stream from the primary concentration. The final concentrate stream is extracted and then used for further processing, such as further treatment, further processing, or storage. The (final) product obtained during product concentration is typically a hydrated ammonium nitrate, which, at appropriate pressure, can form a hydrated melt, particularly with an ammonium nitrate content of 95 wt.% or more.

[0016] In the fourth step (step d)), further ammonia and nitric acid are combined in a spatially separate process from the first neutralization reaction. This further neutralization reaction (secondary neutralization) also generates heat of reaction, thus releasing thermal energy. The resulting product stream is a mass stream, the secondary reaction stream, which contains ammonium nitrate and water and may also contain other components, such as small amounts of the reactants and unavoidable impurities.Just as with the primary reaction stream, it is possible to feed the secondary reaction stream (or at least a portion of it) back into a neutralization reaction by returning it to the original primary neutralization stage (possibly together with the recycled mass stream from the primary neutralization) and / or to the secondary neutralization stage. This also achieves a homogenization of the reaction conditions by improving the removal of any heat. The heat energy released during the additional combination of ammonia and nitric acid in the secondary neutralization reaction is then used to heat the concentrate stream in the third step (product concentration), as the secondary reaction stream transfers heat energy to the concentrate stream.

[0017] The transfer of heat energy from the secondary reaction stream to the concentrate stream can occur in a direct or an indirect step. In a direct step, the heated secondary reaction stream itself, or a partial stream obtained from the secondary reaction stream (in particular a water stream separated during the concentration of the secondary reaction stream), is brought into thermal contact with the concentrate stream, thereby transferring heat energy to the concentrate stream and heating it.

[0018] One material stream is brought into "thermal contact" with another by feeding the two streams to opposite sides of a barrier that is impermeable and heat-permeable (heat-conducting) and – separated from each other by the barrier – bringing them into contact with the barrier, so that heat transfer occurs across the barrier without mass transfer; in this process, the warmer material stream transfers some of its thermal energy to the colder material stream either directly (in a "direct step", i.e., without involving a heat transfer medium) or indirectly (in an "indirect step"), i.e., by bringing the warmer material stream into thermal contact with a colder heat transfer medium stream, whereby thermal energy is transferred from the warmer material stream to the heat transfer medium stream, thereby heating the latter, and the heated heat transfer medium stream is then brought into thermal contact with the colder material stream.In this process, heat energy is transferred from the heated heat transfer fluid stream to the colder fluid stream, thereby heating the latter, while the heat transfer fluid stream is cooled, resulting in an overall transfer of heat energy from the warmer fluid stream to the colder fluid stream. A "heat transfer fluid" is a fluid that absorbs heat energy from one fluid stream in a heat exchanger and releases heat energy to another fluid stream in a different heat exchanger; for example, the fluid that forms the intermediate heat transfer fluid stream.

[0019] Accordingly, the secondary reaction stream or a partial stream derived from it (in particular a water stream separated during the concentration of the secondary reaction stream) transfers thermal energy directly (in a "direct step") to the concentrate stream, i.e., without involving another heat transfer medium (intermediate heat transfer medium). Alternatively, in an "indirect step," the heated secondary reaction stream itself or a partial stream derived from the secondary reaction stream (in particular a water stream separated during the concentration of the secondary reaction stream) can be brought into thermal contact with an intermediate heat transfer medium, whereby thermal energy is transferred to the intermediate heat transfer medium and it is thereby heated.Additionally, the heated intermediate heat transfer fluid stream is brought into thermal contact with the concentrate stream, whereby heat energy is transferred from the heated intermediate heat transfer fluid stream to the concentrate stream, thus heating the latter. In this way, heat energy is transferred from the secondary reaction stream to the intermediate heat transfer fluid stream and from the intermediate heat transfer fluid stream to the concentrate stream – overall, the heat energy is therefore indirectly transferred from the secondary reaction stream to the concentrate stream, with the involvement of the intermediate heat transfer fluid stream.

[0020] The secondary reaction stream cooled in this way then forms the secondary stream, i.e., a mass stream containing the target product ammonium nitrate and water (product stream, reaction product stream) and which has transferred at least some of the heat of reaction from the neutralization to the concentrate stream in a direct or indirect step (and has thus been cooled).

[0021] According to one embodiment of the invention, the initially described process is carried out such that water is separated from the secondary reaction stream, yielding the secondary stream and a water stream. The secondary reaction stream transfers thermal energy to the concentrate stream by heating the concentrate stream in step c). Consequently, water is separated from the secondary reaction stream obtained in step d), yielding a concentrated secondary reaction stream (secondary stream) and a water stream (as a "further" water stream from the secondary concentration). The secondary stream thus contains the (target) product ammonium nitrate at a higher concentration than the secondary reaction stream and has a lower water content than the secondary reaction stream.The separation of water typically occurs in the same way as described in step b) for the water stream from the primary concentration. Here too, the water separation can take place after the secondary neutralization reaction and thus in different parts of the plant (the secondary neutralization reaction therefore occurs in a different part of the plant than the water separation). However, with suitable reaction control, this can also take place in an integrated secondary neutralizer-secondary concentrator. The resulting secondary stream and the water stream from the secondary concentration are then routed separately. The secondary stream can be further treated.Further processing or use of the water stream from the secondary concentration typically occurs in a manner similar to that described in step b) in connection with the processing / use of the water stream from the primary concentration. However, in this configuration, the secondary reaction stream transfers thermal energy to the concentrate stream, so that the thermal energy from the secondary reaction stream is used to heat the concentrate stream in the third step (step c)).The transfer of thermal energy from the secondary reaction stream to the concentrate stream can be achieved by bringing the secondary reaction stream into thermal contact with the concentrate stream (in a direct or indirect step), by bringing the water stream obtained from the secondary reaction stream (the further water stream from the secondary concentration) into thermal contact with the concentrate stream (in a direct or indirect step), or by bringing the secondary stream obtained from the secondary reaction stream into thermal contact with the concentrate stream (in a direct or indirect step). In this way, the thermal energy generated as heat of reaction during secondary neutralization is used particularly efficiently for product concentration.

[0022] According to a further embodiment of the invention, the method described above is carried out such that the water stream obtained from the secondary reaction stream heats the concentrate stream in step c) by bringing the water stream into thermal contact with the concentrate stream, so that the water stream transfers thermal energy to the concentrate stream, thus heating the concentrate stream. In this embodiment, the secondary reaction stream transfers thermal energy to the concentrate stream by bringing the water stream obtained from the secondary reaction stream (the further water stream from the secondary concentration) into thermal contact with the concentrate stream (in a direct or an indirect step).In this way, a large part of the thermal energy generated as heat of reaction in secondary neutralization is used for product concentration in a simple manner, while the separation of water from the secondary reaction stream remains efficient (since the heat energy from the still hot secondary reaction stream is only removed after the water has been separated) and a subsequent concentration of the secondary stream also remains efficient (since no additional heat energy is removed from the secondary stream).

[0023] According to a further embodiment of the invention, the method described above is carried out in such a way that the water stream obtained from the secondary reaction stream heats the concentrate stream in step c) by bringing the water stream into thermal contact with an intermediate heat transfer fluid stream and the water stream transferring heat energy to the intermediate heat transfer fluid stream, so that the water stream heats the intermediate heat transfer fluid stream and a heated intermediate heat transfer fluid stream is obtained, and the heated intermediate heat transfer fluid stream is brought into thermal contact with the concentrate stream and the heated intermediate heat transfer fluid stream transfers heat energy to the concentrate stream, so that the concentrate stream is heated.When transferring thermal energy from the secondary concentration water stream to an intermediate heat transfer fluid stream, which subsequently transfers thermal energy to the concentrate stream, the thermal energy introduced into the concentrate stream can be precisely metered by selecting and directing the intermediate heat transfer fluid. This allows the heat input into the concentrate stream to be partially decoupled from the amount of thermal energy generated during secondary neutralization. In principle, all sufficiently low-viscosity, non-decomposable heat transfer fluids with sufficiently high specific heat capacities, enthalpies of fusion, enthalpies of vaporization, and thermal conductivities, as well as sufficiently high heat transfer coefficients and suitable freezing and boiling points, are suitable as intermediate heat transfer fluids. Water (including steam) or salt solutions such as aqueous ammonium nitrate solutions are particularly suitable.

[0024] According to a further embodiment of the invention, the method described at the outset is carried out such that the secondary reaction stream transfers thermal energy to the concentrate stream by bringing the secondary reaction stream into thermal contact with the concentrate stream, wherein the cooled secondary reaction stream forms the secondary stream. If the secondary reaction stream itself is brought into thermal contact with the concentrate stream (in a direct or indirect step) before the secondary reaction stream is split into the secondary stream and the further water stream, a particularly large portion of the thermal energy that is generated as heat of reaction in the secondary neutralization can be used for product concentration in a simple manner.A potential disadvantage here is that additional heat energy would have to be supplied for the subsequent separation of water, as well as for any further concentration of the secondary stream, since this heat was already removed from the secondary reaction stream before the secondary concentration or any further concentration. However, such a design can be particularly advantageous if the secondary stream is not initially concentrated further (for example, if it is used as an unconcentrated product stream, such as for specific processing steps, or by being returned as a mass flow to the primary or secondary neutralization), since the total heat energy of the secondary reaction stream is significantly higher than that of the secondary stream.

[0025] According to a further embodiment of the invention, one of the aforementioned processes is carried out such that a portion of the concentrate stream is diverted, yielding a recirculated stream which is then returned to the primary neutralization process. In step a), ammonia and nitric acid are combined in this recirculated stream, forming the reaction stream. By returning a portion of the concentrate stream to the primary neutralization process as a recirculated stream, an additional heat storage capacity is provided to absorb the heat energy generated during the primary neutralization. This makes it possible to carry out the primary neutralization at higher concentrations of ammonia and nitric acid without overheating the material stream during the primary neutralization process.As a result of the higher concentrations, production capacity can be increased on the one hand, and on the other hand, smaller amounts of water need to be separated from the product stream, so that less energy is required for concentration.

[0026] According to a further embodiment of the invention, one of the aforementioned methods is carried out such that at least a portion of the secondary stream is recycled into the concentrate stream. By introducing (recycling) the entire secondary stream or at least a portion of the secondary stream into the concentrate stream, a larger total quantity of ammonium nitrate can be obtained from the concentrate stream, since the reaction product of the secondary neutralization is added to the concentrate stream in addition to the reaction product of the primary neutralization. Even if a portion of the concentrate stream is recycled to the primary neutralization as a closed-loop stream, a larger portion of the concentrate stream can thus be added to the product concentration than would be possible if only the concentrate stream obtained from the primary concentration were used.

[0027] According to one embodiment of the invention, the process is also carried out such that at least a portion of the secondary stream is combined with the additional ammonia and nitric acid in step d), so that the secondary reaction stream is formed from the secondary stream. In this case, the secondary stream is thus recycled back into the secondary neutralization process, where it is combined with the reactant streams of the secondary neutralization (the additional ammonia and nitric acid), and the secondary reaction stream is then formed during the secondary neutralization. As a result of recycling this portion of the secondary stream, it is possible to absorb the heat energy generated during the secondary neutralization, allowing the secondary neutralization to be carried out at higher concentrations of ammonia and nitric acid without overheating the material stream during the secondary neutralization process.As a result of the higher concentrations, production capacity can be increased on the one hand, and on the other hand, smaller amounts of water need to be separated from the product stream, so that less energy is required for concentration.

[0028] According to one embodiment of the invention, one of the previously described methods is instead carried out such that it includes diverting at least a portion of the concentrate stream, thereby obtaining a divert stream, wherein the divert stream is combined in step d) with the remaining ammonia and nitric acid, so that the secondary reaction stream is formed from the divert stream. In this case, a portion of the concentrate stream (typically about 5-10% by volume of the concentrate stream, optionally more, and exceptionally even the entire concentrate stream) is introduced into the secondary neutralization, wherein this portion is combined with the reactant streams of the secondary neutralization (the remaining ammonia and nitric acid), and the secondary reaction stream is then formed from this during the secondary neutralization.As a result of introducing part of the concentrate stream, it is possible to absorb the heat energy generated during secondary neutralization (thermal buffer), thereby achieving the advantages described above. If the entire concentrate stream is fed to secondary neutralization, at least a partial stream of the secondary reaction stream obtained in this process (or the secondary stream obtained from the secondary reaction stream) must be fed to the product concentration as a (modified) concentrate stream. Water is then separated from this (modified) concentrate stream in step c), yielding the final concentrate stream and the second water stream. Furthermore, in this case, another partial stream of the secondary reaction stream (or the secondary stream obtained from the secondary reaction stream) can be recycled to the primary and / or secondary neutralization process.

[0029] According to a further embodiment of the invention, one of the aforementioned methods is carried out such that the water stream separated in step b) is subjected to gas scrubbing with a scrubbing liquid, yielding a purified water stream and a contaminated scrubbing liquid stream, and optionally, the contaminated scrubbing liquid stream is discharged from the gas scrubbing process. For example, water, aqueous salt solutions (such as ammonium nitrate or ammonium sulfate), aqueous acids, or alkalis can be used as the scrubbing liquid.The purified water stream can be disposed of or put to further use; for example, the purified water stream can be used as fresh water for the plant for the production of ammonium nitrate, to replace process water or washing liquid required for neutralization in the gas scrubber, or as feed water for another plant, such as an associated plant for the production of nitric acid or ammonia.

[0030] According to a further aspect of the present invention, an apparatus for the production of ammonium nitrate is provided, comprising a process neutralizer, a primary concentrator, and a product concentrator, wherein the primary concentrator is arranged downstream of the process neutralizer and the product concentrator is arranged downstream of the primary concentrator, wherein the process neutralizer is configured and adapted to generate a reaction stream containing ammonium nitrate and water from supplied ammonia and supplied nitric acid, wherein the primary concentrator is configured and adapted to separate water from the reaction stream and obtain a concentrate stream, wherein the product concentrator has a heat exchanger and is configured and adapted to heat the concentrate stream in the product concentrator, wherein the heat exchanger of the product concentrator has a first side and a second side.which are in thermal contact with each other, wherein the first side of the heat exchanger is configured and adapted to pass the concentrate stream through it, and the second side of the heat exchanger is adapted to pass a heat medium stream through it, in order to heat the concentrate stream as it passes through the first side of the heat exchanger in thermal contact with the heat medium stream, and to evaporate water from the concentrate stream and separate it from the concentrate stream. A characteristic feature of the system is that it further includes a secondary neutralizer, which is configured and adapted to generate a secondary reaction stream containing ammonium nitrate and water from additionally supplied ammonia and additionally supplied nitric acid, wherein the heat exchanger of the product concentrator is configured and adapted to heat the concentrate stream in the product concentrator.by the heat medium flow supplying the heat exchanger with thermal energy from the secondary reaction stream and transferring it to the concentrate stream. Accordingly, the invention relates to a plant for the production of ammonium nitrate. A plant for the production of ammonium nitrate is understood to be any plant in which ammonium nitrate is produced. This plant can exist alone (as a single unit) or be integrated into a larger plant complex in which the ammonium nitrate obtained in the plant for the production of ammonium nitrate is further processed or refined, and / or in which the energy of material flows from the plant for the production of ammonium nitrate is utilized, for example, the thermal energy (heat) or mechanical energy (pressure, flow velocity) of the product stream or a by-stream, such as a water stream that has been separated from the product stream.

[0031] The term "configured" refers to the basic structural design of this device, including its dimensions and choice of materials. The term "adapted" refers to any modifications specifically carried out to adapt the device to particular requirements, such as its arrangement within a plant system or the use of additional auxiliary elements necessary for its operation (also within the plant or plant system), such as fluidic or electrical connections, including any valves or switches.

[0032] Such a plant comprises a process neutralizer, a primary concentrator, a product concentrator, and a secondary neutralizer. Typical configurations of a plant for the production of ammonium nitrate, individual components of the plant, their interconnection, and other functional connections are described in particular in the preceding description of the process for the production of ammonium nitrate.

[0033] A neutralizer (neutralization reactor, neutralization stage, neutralized) is a device (a reactor) that is set up and adapted to combine at least one acidic reactant and at least one alkaline reactant supplied to this device into a reaction mixture and to react them together in a (typically spontaneous) neutralization reaction (neutralization), as well as to remove the reaction product from this device, optionally into solution, and to supply any energy required for this or to remove any heat of reaction generated in the process.In its simplest form, a neutralizer is a flow-through vessel with corresponding inlets and outlets. It can also include additional elements, such as internals for flow shaping or heat dissipation; for example, it can be designed as a flow-through reactor with a shell-and-tube heat exchanger. Neutralization can be carried out under different conditions, such as vacuum or pressure neutralization. In pressure neutralization, the gas phase obtained after concentrating the neutralization product has a higher calorific value and a higher energy content usable in other processes than the gas phase obtained after vacuum neutralization. Therefore, the gas phase from stages downstream of pressure neutralization can also be fed into components of a highly integrated system that require a higher energy input.

[0034] A process neutralizer (primary neutralizer) is a neutralizer that carries the main process load and is therefore designed and adapted to produce the majority of the reaction product.

[0035] The secondary neutralizer is a neutralizer that carries a smaller part of the process load than the main process load and is therefore set up and adapted to produce a smaller part of the reaction product than the process neutralizer.

[0036] A concentrator is a device that is set up and adapted to concentrate a fluid stream supplied to this device (for example, a stream in a liquid state, in particular in a low-viscosity, molten, or viscous state), which contains a target component (in this case, ammonium nitrate) and a fluid medium, for example, a solvent, in particular water (which may also contain other components), with regard to a predetermined target component (in this case, ammonium nitrate) by separating at least a part of the fluid medium, so that this target component has a higher concentration in the fluid stream downstream of the device than upstream of the device.In particular, a concentrator can be a device in which at least a part of the solvent contained in the fluid stream, such as water, is transferred into the gas phase and separated from the fluid stream as a result of a change in external parameters such as pressure or temperature or as a result of a change in internal parameters such as the composition of the fluid stream, for example an evaporator, in particular a heat evaporator or a pressure expansion evaporator such as a flash evaporator.

[0037] The primary concentrator is specifically designed and configured to concentrate the reaction stream from the process neutralizer towards the target product—ammonium nitrate—by evaporating water from the incoming reaction stream and removing it from the primary concentrator as a water stream (first water stream), thus obtaining a concentrate stream. This concentrate stream exits the primary concentrator and has a higher concentration of ammonium nitrate than the reaction stream that enters it. The primary concentrator can be of any design, such as a thermal evaporator; however, a pressure-reducing concentrator, for example a flash evaporator, is typically used. The separation of the gas phase from the fluid stream can be achieved, for example, in a cyclone separator.

[0038] The product concentrator is, in particular, a concentrator designed and adapted to concentrate the concentrate stream from the primary concentrator towards the target product by evaporating water from the incoming concentrate stream and discharging it from the product concentrator as a water stream (second water stream), thereby obtaining a final concentrate stream. The final concentrate stream is discharged from the product concentrator and has a higher concentration of ammonium nitrate than the concentrate stream fed into the product concentrator, in particular such that the final product is typically a hydrated ammonium nitrate, which, at appropriate pressure, can form, for example, as a hydrated melt, especially with an ammonium nitrate content of 95 wt.% or more.The product concentrator is an evaporator for thermal evaporation, in particular a tube bundle heat exchanger used as a falling film evaporator.

[0039] 'The process neutralizer has at least one reactant inlet and one

[0040] The reaction stream outlet is open. The reactant inlet is connected to the feed for ammonia and nitric acid (possibly as solutions) and, if necessary, to a feed for a process fluid that serves as a heat storage medium for the heat of reaction generated during primary neutralization, such as a fresh water stream or a product stream recycled as a closed-loop stream.

[0041] The primary concentrator has a reaction stream inlet and a concentrate stream outlet, which are fluidically connected via the primary concentrator; in addition, the primary concentrator also has an outlet for the water stream from the primary concentration, i.e., the first water stream, which is also fluidically connected to the reaction stream inlet via the primary concentrator. The reaction stream outlet of the process neutralizer is fluidly connected to the reaction stream inlet of the primary concentrator.

[0042] Two elements are considered to be "fluidically connected" (also "fluidically connected") in particular if there is a connection between the outlet of one element and the inlet of the other element through which a fluid (in particular a gas or a liquid) can flow, whereby this does not preclude the possibility that this connection includes further elements in the flowable section (conveying section), and can be deflected or otherwise regulated or even shut off by further elements.

[0043] The product concentrator has a concentrate flow inlet and a final concentrate flow outlet, which are fluidically connected via the product concentrator. Furthermore, the product concentrator has an outlet for the water flow from the product concentration, i.e., for the second water flow, which is also fluidically connected to the concentrate flow inlet via the product concentrator.

[0044] The concentrate stream outlet of the primary concentrator is fluidically connected to the concentrate stream inlet of the product concentrator. The concentrate stream is passed through the first side of the product concentrator's heat exchanger and concentrated there, so that the first side of the heat exchanger has a concentrate stream inlet and a final concentrate stream outlet, as well as an outlet for the water stream from the concentrated product, i.e., the second water stream. The concentrate stream inlet of the product concentrator is fluidly connected to (or even identical with) the concentrate stream inlet of the first side of the product concentrator's heat exchanger. The final concentrate stream outlet of the product concentrator is fluidly connected to (or even identical with) the final concentrate stream outlet of the first side of the product concentrator's heat exchanger.The outlet for the water flow from the product concentration is fluidically connected to (or even identical with) the outlet for the water flow on the first side of the product concentrator's heat exchanger. The heat medium flow is directed through the second side of the product concentrator's heat exchanger, so that the second side of the heat exchanger has a heat medium inlet and a heat medium outlet.A "heating medium" is a flowable substance (fluid) that absorbs or releases heat energy from a material stream in a heat exchanger; such a heating medium can either be a process fluid, which forms a material stream whose chemical composition is changed in the plant during the manufacturing process (i.e., the (primary) reaction stream, the concentrate stream, the final concentrate stream, the secondary reaction stream, the secondary stream, or one of the water streams obtained in the primary concentrator, secondary concentrator, or product concentrator), or a heat transfer fluid, which forms, for example, the intermediate heat transfer stream).

[0045] The secondary neutralizer has a reactant inlet and a secondary reaction stream outlet. The reactant inlet is connected to the feed for additional ammonia and nitric acid (optionally in solution) and, if necessary, to a feed for a process fluid that serves as a heat storage medium for the heat of reaction generated during primary neutralization. This fluid could be a fresh water stream or a product stream recirculated as a closed loop. The secondary reaction stream outlet of the secondary neutralizer is fluidically connected to the heat medium inlet of the second side of the product concentrator's heat exchanger in such a way that the secondary reaction stream is used to heat the concentrate stream in the product concentrator by transferring thermal energy from the secondary reaction stream to the concentrate stream.For this purpose, the secondary reaction stream itself is supplied as the heat medium (i) to the heat medium inlet of the second side of the product concentrator and is discharged from the second side of the product concentrator as a (cooled) secondary stream via the heat medium outlet.

[0046] (ii) the further water stream separated from the secondary reaction stream in the secondary concentrator is fed in and discharged from the second side of the product concentrator as a (cooled) further water stream via the heat medium outlet, or

[0047] (iii) an intermediate heat transfer fluid stream is supplied, which has absorbed thermal energy from the secondary reaction stream in an intermediate heat exchanger (either directly from the secondary reaction stream or from the further water stream that was separated from the secondary reaction stream and / or from the secondary stream), and which is discharged from the second side of the product concentrator as a (cooled) intermediate heat transfer fluid stream via the heat transfer medium outlet. Therefore, the secondary reaction stream transfers thermal energy to the concentrate stream, in particular either directly or indirectly.

[0048] According to one embodiment of the invention, the system described above further comprises a secondary concentrator arranged downstream of the secondary neutralizer. This secondary concentrator is configured and adapted to separate water from the secondary reaction stream to obtain the secondary stream and a water stream. The secondary concentrator is fluidically connected to the product concentrator to supply thermal energy from the secondary reaction stream to the heat exchanger of the product concentrator by transferring thermal energy from the water stream obtained from the secondary reaction stream to the concentrate stream. For this purpose, the outlet of the water stream from the secondary concentrator is connected to the heat medium inlet of the second side of the heat exchanger of the product concentrator in such a way that the additional water stream from the secondary concentrator is used to heat the concentrate stream in the product concentrator.by transferring thermal energy from the secondary water stream directly or indirectly to the concentrate stream. For this purpose, the secondary water stream separated from the secondary reaction stream in the secondary concentrator is fed into the heat transfer medium inlet of the second side of the product concentrator and discharged from the second side of the product concentrator as a (cooled) secondary water stream via the heat transfer medium outlet. Alternatively, an intermediate heat transfer medium is supplied, which has absorbed thermal energy from the secondary water stream separated from the secondary reaction stream in an intermediate heat exchanger.and is discharged from the second side of the product concentrator as a (cooled) intermediate heat transfer fluid stream via the heat transfer medium outlet. Consequently, the subsequent water stream transfers thermal energy to the concentrate stream either directly or indirectly; the respective advantages of this design and the following descriptions correspond to the advantages described in connection with the process claims, which can be realized in a particularly simple manner in terms of the apparatus. Unless otherwise specified, the terms "downstream" and "upstream" refer here to the conveying direction of the main material stream that is conveyed through the respective elements; thus, "downstream from the process neutralizer" refers to a direction in the conveying direction of the reaction stream, and "downstream from the primary concentrator" refers to a direction in the conveying direction of the concentrate stream."downstream of the secondary neutralizer" in a direction in the conveying direction of the secondary reaction stream, "upstream of the product concentrator" in a direction against the conveying direction of the concentrate stream, "upstream of the secondary neutralizer" in a direction against the conveying direction of the material streams fed into the secondary neutralizer, "upstream of the concentrate stream inlet" of the product concentrator in a direction against the conveying direction of the concentrate stream, and "upstream of the branch stream inlet of the secondary neutralizer" in a direction against the conveying direction of the material streams fed into the secondary neutralizer.

[0049] According to a further embodiment of the invention, in the system described above, the secondary concentrator is fluidically connected to the product concentrator in order to supply heat energy from the secondary reaction stream to the heat exchanger of the product concentrator by supplying the water stream obtained from the secondary reaction stream to the second side of the heat exchanger of the product concentrator as a heat medium stream, so that when the water stream passes through the second side of the heat exchanger of the product concentrator as a heat medium stream, it transfers heat energy to the concentrate stream and thereby heats the concentrate stream.For this purpose, the outlet of the water flow from the secondary concentrator is connected to the heat medium inlet of the second side of the heat exchanger of the product concentrator in such a way that the additional water flow from the secondary concentrator is used to heat the concentrate flow in the product concentrator by directly transferring thermal energy from the additional water flow to the concentrate flow. To this end, the additional water flow, separated from the secondary reaction flow in the secondary concentrator, is supplied as the heat medium to the heat medium inlet of the second side of the product concentrator and is then discharged from the second side of the product concentrator as a (cooled) additional water flow via the heat medium outlet.

[0050] According to a further embodiment of the invention, the system described above instead has an intermediate heat exchanger which is thermally connected on one side to the secondary concentrator and on the other side to the heat exchanger of the product concentrator and which is set up and adapted to supply heat energy from the secondary reaction stream to the heat exchanger of the product concentrator by transferring heat energy to an intermediate heat transfer medium in the intermediate heat exchanger with the water stream obtained from the secondary reaction stream, wherein the intermediate heat transfer medium is supplied to the second side of the heat exchanger of the product concentrator, so that when the intermediate heat transfer medium passes through the second side of the heat exchanger of the product concentrator, it transfers heat energy to the concentrate stream as a heat transfer medium stream and thereby heats the concentrate stream.For this purpose, the outlet of the water flow from the secondary concentrator is connected to the heat transfer medium inlet of the second side of the heat exchanger of the product concentrator in such a way that the further water flow from the secondary concentrator is used to heat the concentrate flow in the product concentrator by indirectly transferring thermal energy from the further water flow to the concentrate flow. To this end, an intermediate heat transfer medium is supplied to the heat transfer medium inlet of the second side of the product concentrator. This intermediate heat transfer medium has absorbed thermal energy from the further water flow, which was separated from the secondary reaction flow, in an intermediate heat exchanger and is then discharged from the second side of the product concentrator as a (cooled) intermediate heat transfer medium flow via the heat transfer medium outlet.According to a further embodiment of the invention, in the system described at the beginning, the secondary neutralizer is fluidically connected to the heat exchanger of the product concentrator in such a way as to use the secondary reaction stream from the secondary neutralizer to heat the concentrate stream in the product concentrator by supplying the secondary reaction stream to the second side of the heat exchanger of the product concentrator, so that the secondary reaction stream, as it passes through the second side of the heat exchanger of the product concentrator, transfers thermal energy to the concentrate stream as a heat medium stream.For this purpose, the outlet of the secondary reaction stream of the secondary neutralizer is connected to the heat medium inlet of the second side of the heat exchanger of the product concentrator in such a way that the secondary reaction stream from the secondary neutralizer is used to heat the concentrate stream in the product concentrator by directly transferring thermal energy from the secondary reaction stream to the concentrate stream. To this end, the secondary reaction stream itself is supplied as the heat medium to the heat medium inlet of the second side of the product concentrator and is discharged from the second side of the product concentrator as a (cooled) secondary stream via the heat medium outlet; thus, the secondary reaction stream transfers thermal energy directly to the concentrate stream.

[0051] According to a further embodiment of the invention, one of the previously described systems also has a return branch and a circuit return, wherein the return branch is arranged downstream of the primary concentrator and upstream of the product concentrator or upstream of the secondary neutralizer, wherein the return branch is set up and adapted to allow the concentrate flow or the branch flow to pass through it and to divert a partial flow from the respective flow as a circuit return flow and return it to the primary concentrator via the circuit return.Such a return branch can be designed to be regulated or unregulated, for example, via simple connectors (pipe connections) such as T-shaped or Y-shaped connectors, which are either continuously open or can be shut off with appropriate closure devices, such as valves or the like, or as a collection chamber with multiple outlets. The conveyance of the material flow through the recirculation can also be supported by appropriate conveying units, for example, by pumps within the recirculation system.

[0052] According to a further embodiment of the invention, one of the previously described systems also includes a primary recirculation system, wherein the primary recirculation system is arranged downstream of the secondary neutralizer, and wherein the primary recirculation system is configured and adapted to pass through at least a portion of the secondary reaction stream obtained from the secondary reaction stream and to supply it to the process neutralizer as a primary recirculation stream in order to generate the reaction stream from the primary recirculation stream, the supplied ammonia, and the supplied nitric acid. This distributes the heat energy generated in the process neutralizer over a larger quantity of material in the mass flow.

[0053] According to a further embodiment of the invention, the previously described system also has a secondary recirculation, wherein the secondary recirculation is arranged downstream of the secondary neutralizer, wherein the secondary recirculation is set up and adapted to pass at least a part of the secondary stream obtained from the secondary reaction stream through it as a secondary recirculation stream and supply it to the secondary neutralizer in order to generate the secondary reaction stream from the secondary recirculation stream, the additional ammonia supplied and the additional nitric acid supplied.

[0054] According to a further aspect of the present invention, a method for retrofitting an ammonium nitrate production plant is provided, the plant comprising a process neutralizer, a primary concentrator, and a product concentrator, wherein the primary concentrator is arranged downstream of the process neutralizer and the product concentrator is arranged downstream of the primary concentrator, wherein the process neutralizer is configured and adapted to generate a reaction stream containing ammonium nitrate and water from supplied ammonia and supplied nitric acid, wherein the primary concentrator is configured and adapted to separate water from the reaction stream and obtain a concentrate stream, wherein the product concentrator has a heat exchanger and is configured and adapted to heat the concentrate stream through the heat exchanger, thereby evaporating and separating water from the concentrate stream.to obtain a final concentrate stream and a water stream, wherein the heat exchanger of the product concentrator has a first side and a second side which are in thermal contact with each other, the first side of the heat exchanger being configured and adapted to pass the concentrate stream through it, and the second side of the heat exchanger being adapted to pass a heat medium stream through it, in order to heat the concentrate stream as it passes through the first side of the heat exchanger in thermal contact with the heat medium stream and to evaporate water from the concentrate stream and separate it from the concentrate stream. A characteristic feature of the process is that a further step includes the addition of a secondary neutralizer to the system, which is configured and adapted to generate a secondary reaction stream containing ammonium nitrate and water from additionally supplied ammonia and additionally supplied nitric acid.The secondary neutralizer is thermally connected to the second side of the product concentrator's heat exchanger, allowing heat energy from the secondary reaction stream to be transferred to the concentrate stream, thus heating the concentrate stream within the product concentrator. Retrofitting a secondary neutralizer (optionally with a secondary concentrator) provides the product concentrator with sufficient heat energy, derived from the heat of reaction of the neutralization reactions, to enable concentration within the product concentrator without the need for separate heating units such as resistance heaters or burners.

[0055] According to a further aspect of the present invention, a further method for retrofitting an ammonium nitrate production plant is described, the plant comprising a process neutralizer, a primary concentrator, and a product waste concentrator, wherein the primary concentrator is arranged downstream of the process neutralizer and the product waste concentrator is arranged downstream of the primary concentrator, wherein the process neutralizer is configured and adapted to generate a reaction stream containing ammonium nitrate and water from supplied ammonia and supplied nitric acid, wherein the primary concentrator is configured and adapted to separate water from the reaction stream and obtain a concentrate stream, and wherein the product waste concentrator is configured and adapted to heat the concentrate stream and thereby evaporate and separate water from the concentrate stream.to obtain a final concentrate stream and a water stream. A characteristic feature of the process is that it further comprises the step of adding a branch, a product concentrator, and a secondary neutralizer to the plant, wherein the branch is arranged downstream of the primary concentrator and upstream of the product concentrator, and is configured and adapted to divert a partial stream from the concentrate stream. The product concentrator has a heat exchanger, is arranged downstream of the branch, and is configured and adapted to heat the diverted partial stream of the concentrate stream by means of the heat exchanger, thereby evaporating and separating water from the partial stream of the concentrate stream to obtain an additional final concentrate stream and an additional water stream. The heat exchanger of the product concentrator has a first side and a second side.which are in thermal contact with each other, wherein the first side of the heat exchanger is configured and adapted to pass through the partial flow of the concentrate flow, and the second side of the heat exchanger is adapted to pass through a heat medium flow in order to heat the partial flow of the concentrate flow as it passes through the first side of the heat exchanger in thermal contact with the heat medium flow and to evaporate water from the concentrate flow and separate it from the concentrate flow, wherein the secondary neutralizer is configured and adapted to generate a secondary reaction flow containing ammonium nitrate and water from additionally supplied ammonia and additionally supplied nitric acid, wherein the secondary neutralizer is thermally connected to the second side of the heat exchanger of the product concentrator.so that heat energy is transferred from the secondary reaction stream to the concentrate stream and the concentrate stream is heated in the product concentrator.

[0056] In detail, there are numerous possibilities for designing and further developing the methods and the system according to the invention. Reference is made to the claims subordinate to claims 1 and 11, as well as to the following description of advantageous embodiments in conjunction with the drawings, with the aid of which the invention will be described in more detail below without limiting the general inventive concept underlying these embodiments. Individual steps will also be explained, which can be combined almost arbitrarily depending on the desired objectives of the respective method. Further advantages and application possibilities will also become apparent from the exemplary embodiments. The figures show each of these schematically.

[0057] Fig. 1 shows a schematic representation of a conventional process for the production of ammonium nitrate in a conventional ammonium nitrate production plant.

[0058] Fig. 2 shows a schematic representation of a first embodiment of a process according to the invention for the production of ammonium nitrate in a plant according to the invention for the production of ammonium nitrate,

[0059] Fig. 3 shows a schematic representation of a second embodiment of a process according to the invention for the production of ammonium nitrate in a plant according to the invention for the production of ammonium nitrate.

[0060] Fig. 4 shows a schematic representation of a third embodiment of a process according to the invention for the production of ammonium nitrate in a plant according to the invention for the production of ammonium nitrate,

[0061] Fig. 5 shows a schematic representation of a fourth embodiment of a process according to the invention for the production of ammonium nitrate in a plant according to the invention for the production of ammonium nitrate,

[0062] Fig. 6 shows a schematic representation of a fifth embodiment of a process according to the invention for the production of ammonium nitrate in a plant according to the invention for the production of ammonium nitrate,

[0063] Fig. 7 shows a schematic representation of a sixth embodiment of a process according to the invention for the production of ammonium nitrate in a plant according to the invention for the production of ammonium nitrate and

[0064] Fig. 8 shows a schematic representation of a seventh embodiment of a process according to the invention for the production of ammonium nitrate in a plant according to the invention for the production of ammonium nitrate.

[0065] Figure 1 shows a schematic representation of a conventional process for the production of ammonium nitrate in a prior art ammonium nitrate production plant 1. The plant 1 includes a process neutralizer 2 into which ammonia 30 (as a gas or in solution, typically in aqueous solution) and nitric acid 31 (in solution, typically in concentrated aqueous solution) are fed (the streams of ammonia 30 and nitric acid 31 are typically fed to the process neutralizer 2 separately and only mixed together within the process neutralizer 2). In the process neutralizer 2, these substances typically react with each other in a neutralization reaction at a pressure greater than 1 bar a, forming ammonium nitrate and water.In this process, reaction stream 20 is formed, which contains ammonium nitrate and water, as well as small amounts of unreacted ammonia and unreacted nitric acid (and unavoidable impurities). Reaction stream 20—essentially hydrated ammonium nitrate—exists in liquid form at higher temperatures, typically as an aqueous solution, a hydrated melt, or an aqueous melt, the properties of which depend strongly on the specific concentrations of ammonium nitrate and water, as well as the respective temperature and pressure.

[0066] The reaction stream 20 is discharged from the process neutralizer 2 and flows downstream from the process neutralizer 2 into the primary concentrator 3, which operates at a lower pressure than the process neutralizer, approximately sub-atmospheric pressure, for example, 400 mbar a. Upon entering the primary concentrator 3, the reaction stream 20 experiences a pressure reduction, causing some of the water present in the reaction stream 20 to evaporate into the gas phase and be separated from the reaction stream 20, for example, in a cyclone separator. The separated water is discharged as steam from the primary concentrator 3 in water stream 42. The remaining concentrated reaction stream 20, known as concentrate stream 21, exits the primary concentrator 3 and is discharged downstream from the primary concentrator 3 into the product concentrator 4.

[0067] The product concentrator 4 has a heat exchanger with a first side and a second side (not shown). The first and second sides of the heat exchanger are in thermal contact with each other. The concentrate stream 21 is fed to the first side of the heat exchanger, passes through it, and then exits. Simultaneously, a heated heat medium stream (not shown) is fed to the second side of the heat exchanger, passes through it, and finally exits.As the concentrate stream 21 and the heat medium stream pass through the respective sides of the heat exchanger in the product concentrator 4, the heated heat medium stream comes into thermal contact with the concentrate stream 21, so that heat is transferred from the heated heat medium stream to the concentrate stream 21 without any mass transfer occurring between the concentrate stream 21 and the heat medium stream. The heat medium stream therefore leaves the heat exchanger cooled, while the concentrate stream 21 is heated in the heat exchanger. As a result of the heating of the concentrate stream 21, some of the water present in the concentrate stream 21 evaporates into the gas phase and separates from the concentrate stream 21.The separated water is discharged as steam from the product concentrator 4 in water stream 43, leaving the concentrated concentrate stream 21, which leaves the product concentrator 4 as final concentrate stream 22 and is put to further use, for example by being introduced into a storage vessel (not shown).

[0068] According to the prior art, heat is supplied to the concentrate stream 21 in the product concentrator 4 by means of a heated heat medium stream. The heat medium stream is heated by a heating device (not shown), which could be, for example, a burner operated with hydrocarbons, hydrogen, or ammonia as fuel, an electric heater, or another heat exchanger; alternatively, the heat medium stream can also be heated in another part of the plant complex (and thus outside of plant 1).

[0069] Figure 2 shows a schematic representation of a first embodiment of a process according to the invention for the production of ammonium nitrate in a plant according to the invention for the production of ammonium nitrate, which is derived from the process shown in Figure 1 (where the same reference numerals denote the same elements). In contrast to the arrangement shown in Figure 1, in Figure 2 the entire concentrate stream 21 is not directed from the primary concentrator 3 to the product concentrator 4. Instead, a partial stream of the concentrate stream 21 is branched off downstream of the primary concentrator 3 and upstream of the product concentrator 4 at a T-shaped pipe connection and fed to the secondary neutralizer 5 as a branch stream 44, which contains ammonium nitrate, water, small amounts of ammonia and nitric acid (as well as unavoidable impurities).In the secondary neutralizer 5, additional ammonia 32 and nitric acid 33 are added to the branch stream 44, triggering a further neutralization reaction. In this reaction, the additional ammonia and nitric acid react to form additional ammonium nitrate, releasing heat in the process. This forms the secondary reaction stream 23, which, in addition to the components of the branch stream 44, primarily contains additional ammonium nitrate and water. The secondary reaction stream 23 is heated by the heat of reaction generated during the further neutralization in the secondary neutralizer 5.

[0070] The portion of concentrate stream 21 that was not diverted is fed to the first side of the heat exchanger of product concentrator 4. The heated secondary reaction stream 23 is fed as a heat transfer medium to the second side of the heat exchanger of product concentrator 4, where it comes into thermal contact (without mass transfer) with concentrate stream 21 and heats the latter. As a result, secondary reaction stream 23 cools down, forming secondary stream 24, which exits product concentrator 4. By utilizing the heat of reaction generated during the neutralization reaction in the secondary neutralizer 5, it is possible to concentrate concentrate stream 21 to the final concentrate stream 22 without requiring additional energy sources to heat the heat transfer medium.

[0071] Figure 3 shows a schematic representation of a second embodiment of a process according to the invention for the production of ammonium nitrate in a plant according to the invention for the production of ammonium nitrate, which is derived from the embodiment shown in Figure 2 (where the same reference numerals denote the same elements). In contrast to the arrangement shown in Figure 2, in the variant shown in Figure 3, the entire secondary reaction stream 23 is not introduced into the heat exchanger as a heat medium stream; rather, the secondary reaction stream 23 is first fed to a secondary concentrator 6, which is arranged downstream of the secondary neutralizer 5. In the secondary concentrator 6, water is separated from the secondary reaction stream 23, typically in a heat exchanger, in particular a shell and tube heat exchanger, often also as part of a further pressure reduction.In this process, water from the secondary reaction stream 23 is transferred into the gas phase and separated from the secondary reaction stream 23 as a further water stream 40. The secondary stream 24 is formed from the thus concentrated and cooled secondary reaction stream 23. This secondary stream 24 is fed to the primary concentrator 3 via primary recirculation 11 as primary recirculation stream 47, for example, at the end of the primary concentrator 3 (alternatively, feeding at other positions is also possible, such as downstream of the primary concentrator 3 or within the primary concentrator 3, or possibly even downstream of the primary concentrator 3). The further water stream 40 separated in the secondary concentrator 6 is thus a partial stream of the secondary reaction stream 23 and is fed as a heat medium stream to the second side of the heat exchanger of the product concentrator 4.In the heat exchanger of product concentrator 4, it comes into thermal contact with the partial flow of concentrate stream 21, which is fed to the first side of the heat exchanger of product concentrator 4, and heats the latter. In the process, the subsequent water stream 40 cools down and leaves the product concentrator 4 as a cooled water stream 40. Alternatively, or additionally, the primary return stream can also be fed to the process neutralizer in order to generate the reaction stream from the primary return stream, the added ammonia, and the added nitric acid, thus creating a thermal buffering effect in the process neutralizer.

[0072] Figure 4 shows a schematic representation of a third embodiment of a process according to the invention for the production of ammonium nitrate in a plant according to the invention for the production of ammonium nitrate, which is derived from the embodiment shown in Figure 3 (where the same reference numerals denote the same elements). In contrast to the arrangement shown in Figure 3, in the variant shown in Figure 4, the further water stream 40 obtained from the secondary reaction stream 23 is not itself used as a heat medium stream; rather, the further water stream (not shown) is first fed, after separation from the secondary stream 24 in the secondary concentrator 6, to an intermediate heat exchanger 13, which is integrated into the secondary concentrator 6.The water flow is brought into thermal contact with an intermediate heat transfer fluid flow 41, whereby the water flow transfers thermal energy to the intermediate heat transfer fluid flow 41, thereby heating the latter; the cooled water flow is discharged from the system. The heated intermediate heat transfer fluid flow 41 is then fed to the second side of the heat exchanger of the product concentrator 4 as a heat transfer medium flow, so that its heat is transferred to the concentrate flow 21 and heats it to obtain a concentrated concentrate flow 21 as the final concentrate flow 22. The intermediate heat transfer fluid flow 41 is cooled and leaves the product concentrator 4. The secondary flow 24 is not cooled but remains at a higher temperature level and is thus passed on to the primary concentrator 3.

[0073] Figure 5 shows a schematic representation of a fourth embodiment of a process according to the invention for the production of ammonium nitrate in an ammonium nitrate production plant according to the invention, which is derived from the embodiment shown in Figure 3 (where the same reference numerals denote the same elements). In contrast to the arrangement shown in Figure 3, in the variant shown in Figure 5, no branch stream is taken from the concentrate stream 21 and fed to the secondary neutralizer 5. Rather, in Figure 5, the entire concentrate stream 21 is fed to the product concentrator 4. Furthermore, in Figure 5, the secondary stream 24 obtained from the secondary reaction stream 23 is not fed to the primary concentrator 3 via primary recirculation 11 as primary recirculation stream 47, but rather to the secondary concentrator 5 via secondary recirculation 12 as secondary recirculation stream 48.In the secondary neutralizer 5, the additional ammonia 32 and nitric acid 33 are added to the secondary recirculation stream 48, so that the (secondary) neutralization reaction takes place there, releasing heat and forming the secondary reaction stream 23, which is then fed to the secondary concentrator 6. To prevent an accumulation of ammonium nitrate in the recirculation stream formed from the reaction stream 23 and the secondary recirculation stream 48 / secondary stream 24, a partial stream is continuously diverted from the secondary recirculation stream 48 and fed as the return feed stream 49 to the reaction stream 20 downstream of the process neutralizer 2 and upstream of the primary concentrator 3.

[0074] Figure 6 shows a schematic representation of a fifth embodiment of a process according to the invention for the production of ammonium nitrate in an ammonium nitrate production plant according to the invention, which is derived from the embodiment shown in Figure 4 (where the same reference numerals denote the same elements). In contrast to the arrangement shown in Figure 4, in the variant shown in Figure 6, after branching off a partial stream 44 from the concentrate stream 21, a further partial stream is branched off and fed to the process neutralizer 2 via recirculation 10 as recirculation stream 46 (in principle, the partial stream forming the branch stream 44 can also be branched off from the concentrate stream 21 downstream of the branching off of the partial stream as recirculation stream 46, or even at the same point).In the process neutralizer 2, ammonia 30 and nitric acid 31 are added to the recirculation stream 46, so that the primary neutralization reaction takes place in the recirculation stream 46, releasing heat and forming the reaction stream 20, which is then fed to the primary concentrator 3.

[0075] Figure 7 shows a schematic representation of a sixth embodiment of a process according to the invention for the production of ammonium nitrate in an ammonium nitrate production plant according to the invention, which is derived from the embodiment shown in Figure 2 (where the same reference numerals denote the same elements). In contrast to the arrangement shown in Figure 2, in the variant shown in Figure 7, the branch stream 44 is not branched off from the concentrate stream 21 and fed to the secondary neutralizer 5. Instead, in Figure 7, a partial stream of the secondary stream 24 is fed to the secondary concentrator 5 via secondary return 12 as secondary return stream 48.In the secondary neutralizer 5, the additional ammonia 32 and the additional nitric acid 33 are added to the secondary return stream 48, so that the secondary neutralization reaction takes place there, in which heat is released and the secondary reaction stream 23 is formed, which is then fed to the secondary concentrator 6. For this purpose, the secondary stream 24 obtained from the secondary reaction stream 23 by cooling in the heat exchanger of the product concentrator 4 is fed to a branch from which two partial streams are discharged. One of these partial streams forms the secondary return stream 48, and the other partial stream forms a return feed stream 49. To prevent an accumulation of ammonium nitrate in the cycle stream formed from the reaction stream 23 and the secondary return stream 48, the return feed stream 49 is fed to the concentrate stream 21 downstream of the primary concentrator 3 and upstream of the product concentrator 4. Further details are shown in Fig.7 A partial stream is diverted from the concentrate stream 21 (upstream, downstream, or at the point where the return stream 49 is fed into the concentrate stream 21) and fed to the process neutralizer 2 via the recirculation 10 as recirculation stream 46. In the process neutralizer 2, ammonia 30 and nitric acid 31 are added to the recirculation stream 46, so that a neutralization reaction takes place there, in which heat is released and the reaction stream 20 is formed, which is then fed to the primary concentrator 3.

[0076] Figure 8 shows a schematic representation of a seventh embodiment of a process according to the invention for the production of ammonium nitrate in a plant according to the invention for the production of ammonium nitrate, which is derived from the embodiment shown in Figure 7 (where the same reference numerals denote the same elements). In contrast to the arrangement shown in Figure 7, in the variant shown in Figure 8, an additional partial stream is diverted from the concentrate stream 21 (upstream, downstream, or at one of the diversions where the return stream 49 is added to the concentrate stream 21 or the recirculation stream 46 is diverted from the concentrate stream 21) and fed as concentrate stream 21 to a product concentrator 7, where the supplied concentrate stream 21 is further concentrated and an additional final concentrate stream 45 and an additional water stream 50 are obtained.Such a configuration can arise, for example, if, as part of a capacity expansion, an existing plant 1 for the production of ammonium nitrate is to be converted, for which purpose a further plant section for concentration is added to the already existing “old” product concentrator - the product old concentrator 7 - which contains the secondary neutralizer 5 in addition to the product concentrator 4 and which plant section is additionally arranged in parallel to the already existing product old concentrator 7.

[0077] Reference symbol list

[0078] 1 Annex

[0079] 2 Process neutralizer

[0080] 3 Primary Concentrator

[0081] 4 Product Concentrator

[0082] 5 Secondary neutralizer

[0083] 6 Secondary concentrator

[0084] 7 Product waste concentrator

[0085] 10. Circulation

[0086] 11 Primary Recirculation

[0087] 12 Secondary recirculation

[0088] 13 Intermediate heat exchangers

[0089] 14 washermen

[0090] 20 reaction stream

[0091] 21 Concentrate stream

[0092] 22 Final concentrate stream

[0093] 23 secondary reaction stream

[0094] 24 Secondary current

[0095] 30 Ammonia

[0096] 31 Nitric acid

[0097] 32 more ammonia

[0098] 33 more nitric acids

[0099] 40 (additional) water flow (from secondary concentration)

[0100] 41 Intermediate heat transfer fluid flow

[0101] 42 (first) water stream (from primary concentration)

[0102] 43 (second) water stream (from product concentration)

[0103] 44 Branch current

[0104] 45 additional final concentrate stream

[0105] 46 Return current

[0106] 47 Primary feedback current

[0107] 48 Secondary feedback current

[0108] 49 Return current

[0109] 50 additional water flow (from old product concentration)

Claims

Claims 1. A process for the production of ammonium nitrate, comprising the steps: a) combining ammonia (30) and nitric acid (31), yielding a reaction stream (20) containing ammonium nitrate and water; b) separating water from the reaction stream (20), yielding a concentrate stream (21) and a water stream (42); c) heating the concentrate stream (21) and separating water from the concentrate stream (21), yielding a final concentrate stream (22) and a water stream (43), characterized in that the process further comprises: d) additionally combining further ammonia (32) and further nitric acid (33), yielding a secondary reaction stream (23) containing ammonium nitrate and water with the release of heat energy.wherein the heat energy released in step d) during the additional combination of further ammonia (32) and further nitric acid (33) is used to heat the concentrate stream (21) in step c) by the secondary reaction stream (23) transferring heat energy to the concentrate stream (21) and then forming a secondary stream (24).

2. Method according to claim 1, wherein water is separated from the secondary reaction stream (23), the secondary stream (24) and a water stream (40) are obtained, wherein the secondary reaction stream (23) transfers heat energy to the concentrate stream (21) by the water stream (40) obtained from the secondary reaction stream (23) heating the concentrate stream (21) in step c).

3. Method according to claim 2, wherein the water stream (40) obtained from the secondary reaction stream (23) heats the concentrate stream (21) in step c) by bringing the water stream (40) into thermal contact with the concentrate stream (21) such that the water stream (40) transfers heat energy to the concentrate stream (21) so that the concentrate stream (21) is heated.

4. Method according to claim 2, wherein the water stream (40) obtained from the secondary reaction stream (23) heats the concentrate stream (21) in step c), by bringing the water stream (40) into thermal contact with an intermediate heat transfer fluid stream (41) and the water stream (40) transferring heat energy to the intermediate heat transfer fluid stream (41), so that the water stream (40) heats the intermediate heat transfer fluid stream (41) and a heated intermediate heat transfer fluid stream (41) is obtained, and the heated intermediate heat transfer fluid stream (41) is brought into thermal contact with the concentrate stream (21) and the heated intermediate heat transfer fluid stream (41) transfers heat energy to the concentrate stream (21), so that the concentrate stream (21) is heated.

5. Method according to claim 1, wherein the secondary reaction stream (23) transfers heat energy to the concentrate stream (21) by bringing the secondary reaction stream (23) into thermal contact with the concentrate stream (21), wherein the cooled secondary reaction stream (23) forms the secondary stream (24).

6. Method according to any one of claims 1 to 5, wherein a portion of the concentrate stream (21) is diverted, yielding a recirculation stream (46) which is recirculated, so that in step a) ammonia (30) and nitric acid (31) are combined in the recirculation stream (46), forming the reaction stream (20).

7. Method according to any one of claims 1 to 6, wherein at least a part of the secondary stream (24) is returned to the concentrate stream (21).

8. Method according to any one of claims 1 to 6, wherein at least a part of the secondary stream (24) is combined in step d) with the further ammonia (32) and the further nitric acid (33) so that the secondary reaction stream (23) is formed from the secondary stream (24).

9. Method according to any one of claims 1 to 7, further comprising a branching off at least a part of the concentrate stream (21) wherein a branch stream (44) is obtained, wherein the branch stream (44) is combined in step d) with the further ammonia (32) and the further nitric acid (33) such that the secondary reaction stream (23) is formed from the branch stream (44).

10. Method according to any one of claims 1 to 9, wherein the water stream (42) separated in step b) is subjected to gas scrubbing with a scrubbing liquid, yielding a purified water stream and a contaminated scrubbing liquid stream, and wherein optionally the contaminated scrubbing liquid stream is discharged from the gas scrubbing.

11. Plant (1) for the production of ammonium nitrate, the plant (1) comprising a process neutralizer (2), a primary concentrator (3) and a product concentrator (4), wherein the primary concentrator (3) is arranged downstream of the process neutralizer (2) and the product concentrator (4) is arranged downstream of the primary concentrator (3), wherein the process neutralizer (2) is configured and adapted to generate a reaction stream (20) containing ammonium nitrate and water from supplied ammonia (30) and supplied nitric acid (31), wherein the primary concentrator (3) is configured and adapted to separate water from the reaction stream (20) and obtain a concentrate stream (21), wherein the product concentrator (4) has a heat exchanger and is configured and adapted to heat the concentrate stream (21) in the product concentrator (4), wherein the heat exchanger of the product concentrator (4) has a first side and a second side,which are in thermal contact with each other, wherein the first side of the heat exchanger is configured and adapted to pass the concentrate stream (21) through it, and the second side of the heat exchanger is adapted to pass a heat medium stream through it in order to heat the concentrate stream (21) as it passes through the first side of the heat exchanger in thermal contact with the heat medium stream and to evaporate water from the concentrate stream (21) and to separate water from the concentrate stream (21), characterized in that the system (1) further comprises a secondary neutralizer (5) which is configured and adapted to generate a secondary reaction stream (23) containing ammonium nitrate and water from additionally supplied ammonia (32) and additionally supplied nitric acid (33), wherein the heat exchanger of the product concentrator (4) is configured and, is adapted to heat the concentrate stream (21 ) in the product concentrator (4) by supplying heat energy from the secondary reaction stream (23) to the heat exchanger and transferring it to the concentrate stream (21 ).

12. Plant (1) according to claim 11, wherein the plant (1) further comprises a secondary concentrator (6) arranged downstream of the secondary neutralizer (5) and configured and adapted to separate water from the secondary reaction stream (23) to obtain the secondary stream (24) and a water stream (40), wherein the secondary concentrator (6) is fluidically connected to the product concentrator (4) to supply heat energy from the secondary reaction stream (23) to the heat exchanger of the product concentrator (4) by the water stream (40) obtained from the secondary reaction stream (23) transferring heat energy to the concentrate stream (21).

13. Plant (1) according to claim 12, wherein the secondary concentrator (6) is fluidically connected to the product concentrator (4) in order to supply heat energy from the secondary reaction stream (23) to the heat exchanger of the product concentrator (4) by supplying the water stream (40) obtained from the secondary reaction stream (23) to the second side of the heat exchanger of the product concentrator (4) as a heat medium stream, so that the water stream (40), when passing through the second side of the heat exchanger of the product concentrator (4), transfers heat energy to the concentrate stream (21) and thereby heats the concentrate stream (21).

14. Plant (1) according to claim 12, wherein the plant (1) further comprises an intermediate heat exchanger (13) which is thermally connected on one side to the secondary concentrator (6) and on the other side to the heat exchanger of the product concentrator (4) and which is configured and adapted to supply the heat exchanger of the product concentrator (4) with thermal energy from the secondary reaction stream (23) by transferring thermal energy from the water stream (40) obtained from the secondary reaction stream (23) to an intermediate heat transfer medium in the intermediate heat exchanger (13), wherein the Intermediate heat transfer fluid of the second side of the heat exchanger of the product concentrator (4) is supplied so that the intermediate heat transfer fluid is passed through the second side of the heat exchanger of the The product concentrator (4) transfers heat energy to the concentrate stream (21) as a heat medium stream, thereby heating the concentrate stream (21).

15. Plant (1) according to claim 11, wherein the secondary neutralizer (5) is fluidically connected to the heat exchanger of the product concentrator (4) in such a way as to use the secondary reaction stream (23) from the secondary neutralizer (5) to heat the concentrate stream (21) in the product concentrator (4) by supplying the secondary reaction stream (23) to the second side of the heat exchanger of the product concentrator (4), such that the secondary reaction stream (23) transfers heat energy to the concentrate stream (21) as a heat medium stream when passing through the second side of the heat exchanger of the product concentrator (4).

16. Plant (1) according to any one of claims 11 to 15, wherein the plant (1) has a return branch and a circuit return (10), wherein the return branch is arranged downstream of the primary concentrator (3) and upstream of the product concentrator (4) or upstream of the secondary neutralizer (5), wherein the return branch is configured and adapted to allow the concentrate flow (21) or the branch flow to pass through it and to take a partial flow from the respective flow as a circuit return flow (46) and return it to the primary concentrator (3) via the circuit return (10).

17. Plant (1) according to any one of claims 11 to 16, wherein the plant (1) has a primary recirculation (11), wherein the primary recirculation (11) is arranged downstream of the secondary neutralizer (5), wherein the primary recirculation (11) is configured and adapted to pass through at least a part of the secondary stream (24) obtained from the secondary reaction stream (23) and to supply it as a primary recirculation stream to the process neutralizer (2) in order to generate the reaction stream (20) from the primary recirculation stream, the supplied ammonia (30) and the supplied nitric acid (31).

18. Plant (1) according to any one of claims 11 to 16, wherein the plant (1) has a secondary recirculation (12), wherein the secondary recirculation (12) is arranged downstream of the secondary neutralizer (5), wherein the secondary recirculation (12) is configured and adapted to pass through at least a part of the secondary stream (24) obtained from the secondary reaction stream (23) and to supply it to the secondary neutralizer (5) as a secondary recirculation stream (48) in order to generate the secondary reaction stream (23) from the secondary recirculation stream (48), the additional ammonia (32) supplied and the additional nitric acid (33) supplied.

19. Method for converting a plant (1) for the production of ammonium nitrate, the plant (1) comprising a process neutralizer (2), a primary concentrator (3) and a product concentrator (4), wherein the primary concentrator (3) is arranged downstream of the process neutralizer (2) and the product concentrator (4) is arranged downstream of the primary concentrator (3), wherein the process neutralizer (2) is configured and adapted to generate a reaction stream (20) containing ammonium nitrate and water from supplied ammonia (30) and supplied nitric acid (31), wherein the primary concentrator (3) is configured and adapted to separate water from the reaction stream (20) and obtain a concentrate stream (21), wherein the product concentrator (4) has a heat exchanger and is configured and adapted to heat the concentrate stream (21) through the heat exchanger and thereby to evaporate and separate water from the concentrate stream (21 ),to obtain a final concentrate stream (22) and a water stream (43), wherein the heat exchanger of the product concentrator (4) has a first side and a second side which are in thermal contact with each other, wherein the first side of the heat exchanger is configured and adapted to allow the concentrate stream (21) to pass through it, and the second side of the heat exchanger is adapted to allow a heat medium stream to pass through it, in order to bring the concentrate stream (21) into thermal contact with the heat medium stream as it passes through the first side of the heat exchanger, heating and evaporating water from the concentrate stream (21) and separating it from the concentrate stream (21), characterized in that a secondary neutralizer (5) is added to the system (1), which is set up and adapted to generate a secondary reaction stream (23) containing ammonium nitrate and water from additionally supplied ammonia (32) and additionally supplied nitric acid (33), wherein the secondary neutralizer (5) is thermally connected to the second side of the heat exchanger of the product concentrator (4), so that thermal energy from the secondary reaction stream (23) is transferred to the concentrate stream (21) and the concentrate stream (21) is heated in the product concentrator (4).

20. Method for converting a plant (1) for the production of ammonium nitrate, the plant (1) comprising a process neutralizer (2), a primary concentrator (3) and a product waste concentrator (7), wherein the primary concentrator (3) is arranged downstream of the process neutralizer (2) and the product waste concentrator (7) is arranged downstream of the primary concentrator (3), wherein the process neutralizer (2) is configured and adapted to generate a reaction stream (20) containing ammonium nitrate and water from supplied ammonia (30) and supplied nitric acid (31), wherein the primary concentrator (3) is configured and adapted to separate water from the reaction stream (20) and obtain a concentrate stream (21), and wherein the product waste concentrator (7) is configured and adapted to heat the concentrate stream (21) and thereby remove water from the concentrate stream (21) to evaporate and separate,to obtain a final concentrate stream (22) and a water stream (43), characterized in that a branch, a product concentrator (4) and a secondary neutralizer (5) is added to the system (1), wherein the branch is arranged downstream of the primary concentrator (3) and upstream of the product waste concentrator (7) and is set up and adapted to divert a partial stream from the concentrate stream (21), wherein the product concentrator (4) has a heat exchanger, is arranged downstream of the branch and is configured and adapted to heat the partial stream of the concentrate stream (21) branched off from the concentrate stream (21) through the heat exchanger and thereby evaporate and separate water from the partial stream of the concentrate stream (21) to obtain an additional final concentrate stream (45) and an additional water stream (50), wherein the heat exchanger of the product concentrator (4) has a first side and a second side which are in thermal contact with each other, wherein the first side of the heat exchanger is configured and adapted to pass through the partial stream of the concentrate stream (21) and the second side of the heat exchanger is adapted to pass through a heat medium stream,to heat the partial stream of the concentrate stream (21) as it passes through the first side of the heat exchanger in thermal contact with the heat medium stream and to evaporate water from the concentrate stream (21) and separate it from the concentrate stream (21), wherein the secondary neutralizer (5) is set up and adapted to generate a secondary reaction stream (23) containing ammonium nitrate and water from additionally supplied ammonia and additionally supplied nitric acid (33), wherein the secondary neutralizer (5) is thermally connected to the second side of the heat exchanger of the product concentrator (4) so ​​that thermal energy from the secondary reaction stream (23) is transferred to the concentrate stream (21) and the concentrate stream (21) is heated in the product concentrator (4).

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